/* classes: h_files */ #ifndef SCM_STRINGS_H #define SCM_STRINGS_H /* Copyright (C) 1995-1998, 2000, 2001, 2004-2006, 2008-2011, 2013, * 2015-2018 Free Software Foundation, Inc. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public License * as published by the Free Software Foundation; either version 3 of * the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA * 02110-1301 USA */ #include "libguile/__scm.h" /* String representation. A string is a piece of a stringbuf. A stringbuf can be used by more than one string. When a string is written to and the stringbuf of that string is used by more than one string, a new stringbuf is created. That is, strings are copy-on-write. This behavior can be used to make the substring operation quite efficient. The implementation is tuned so that mutating a string is costly, but just reading it is cheap and lock-free. There are also mutation-sharing strings. They refer to a part of an ordinary string. Writing to a mutation-sharing string just writes to the ordinary string. Internal, low level interface to the character arrays - Use scm_i_is_narrow_string to determine is the string is narrow or wide. - Use scm_i_string_chars or scm_i_string_wide_chars to get a pointer to the byte or scm_t_wchar array of a string for reading. Use scm_i_string_length to get the number of characters in that array. The array is not null-terminated. - The array is valid as long as the corresponding SCM object is protected but only until the next SCM_TICK. During such a 'safe point', strings might change their representation. - Use scm_i_string_start_writing to get a version of the string ready for reading and writing. This is a potentially costly operation since it implements the copy-on-write behavior. When done with the writing, call scm_i_string_stop_writing. You must do this before the next SCM_TICK. (This means, before calling almost any other scm_ function and you can't allow throws, of course.) - New strings can be created with scm_i_make_string or scm_i_make_wide_string. This gives access to a writable pointer that remains valid as long as nobody else makes a copy-on-write substring of the string. Do not call scm_i_string_stop_writing for this pointer. - Alternately, scm_i_string_ref and scm_i_string_set_x can be used to read and write strings without worrying about whether the string is narrow or wide. scm_i_string_set_x still needs to be bracketed by scm_i_string_start_writing and scm_i_string_stop_writing. Legacy interface - SCM_STRINGP is just scm_is_string. - SCM_STRING_CHARS uses scm_i_string_writable_chars and immediately calls scm_i_stop_writing, hoping for the best. SCM_STRING_LENGTH is the same as scm_i_string_length. SCM_STRING_CHARS will throw an error for strings that are not null-terminated. There is no wide version of this interface. */ /* A type indicating what strategy to take when string locale conversion is unsuccessful. */ typedef enum { SCM_FAILED_CONVERSION_ERROR = SCM_ICONVEH_ERROR, SCM_FAILED_CONVERSION_QUESTION_MARK = SCM_ICONVEH_QUESTION_MARK, SCM_FAILED_CONVERSION_ESCAPE_SEQUENCE = SCM_ICONVEH_ESCAPE_SEQUENCE } scm_t_string_failed_conversion_handler; SCM_INTERNAL SCM scm_nullstr; SCM_INTERNAL scm_t_string_failed_conversion_handler scm_i_default_string_failed_conversion_handler (void); SCM_API SCM scm_string_p (SCM x); SCM_API SCM scm_string (SCM chrs); SCM_API SCM scm_make_string (SCM k, SCM chr); SCM_API SCM scm_string_length (SCM str); SCM_API SCM scm_string_utf8_length (SCM str); SCM_API SCM scm_string_bytes_per_char (SCM str); SCM_API SCM scm_string_ref (SCM str, SCM k); SCM_API SCM scm_string_set_x (SCM str, SCM k, SCM chr); SCM_API SCM scm_substring (SCM str, SCM start, SCM end); SCM_API SCM scm_substring_read_only (SCM str, SCM start, SCM end); SCM_API SCM scm_substring_shared (SCM str, SCM start, SCM end); SCM_API SCM scm_substring_copy (SCM str, SCM start, SCM end); SCM_API SCM scm_string_append (SCM args); SCM_API SCM scm_from_stringn (const char *str, size_t len, const char *encoding, scm_t_string_failed_conversion_handler handler); SCM_API SCM scm_c_make_string (size_t len, SCM chr); SCM_API size_t scm_c_string_length (SCM str); SCM_API size_t scm_c_string_utf8_length (SCM str); SCM_API size_t scm_c_symbol_length (SCM sym); SCM_API SCM scm_c_string_ref (SCM str, size_t pos); SCM_API void scm_c_string_set_x (SCM str, size_t pos, SCM chr); SCM_API SCM scm_c_substring (SCM str, size_t start, size_t end); SCM_API SCM scm_c_substring_read_only (SCM str, size_t start, size_t end); SCM_API SCM scm_c_substring_shared (SCM str, size_t start, size_t end); SCM_API SCM scm_c_substring_copy (SCM str, size_t start, size_t end); /* Use locale encoding for user input, user output, or interacting with the C library. Use latin1 for ASCII, and for literals in source code. Use utf8 for interaction with modern libraries which deal in UTF-8. Otherwise use scm_to_stringn or scm_from_stringn with a specific encoding. */ SCM_API SCM scm_from_locale_string (const char *str); SCM_API SCM scm_from_locale_stringn (const char *str, size_t len); SCM_API SCM scm_take_locale_string (char *str); SCM_API SCM scm_take_locale_stringn (char *str, size_t len); SCM_API char *scm_to_locale_string (SCM str); SCM_API char *scm_to_locale_stringn (SCM str, size_t *lenp); SCM_API SCM scm_from_latin1_string (const char *str); SCM_API SCM scm_from_latin1_stringn (const char *str, size_t len); SCM_API char *scm_to_latin1_string (SCM str); SCM_API char *scm_to_latin1_stringn (SCM str, size_t *lenp); SCM_API char *scm_to_utf8_string (SCM str); SCM_API char *scm_to_utf8_stringn (SCM str, size_t *lenp); SCM_API SCM scm_from_utf8_string (const char *str); SCM_API SCM scm_from_utf8_stringn (const char *str, size_t len); SCM_API scm_t_wchar *scm_to_utf32_string (SCM str); SCM_API scm_t_wchar *scm_to_utf32_stringn (SCM str, size_t *lenp); SCM_API SCM scm_from_utf32_string (const scm_t_wchar *str); SCM_API SCM scm_from_utf32_stringn (const scm_t_wchar *str, size_t len); SCM_API char *scm_to_port_string (SCM str, SCM port); SCM_API char *scm_to_port_stringn (SCM str, size_t *lenp, SCM port); SCM_API SCM scm_from_port_string (const char *str, SCM port); SCM_API SCM scm_from_port_stringn (const char *str, size_t len, SCM port); SCM_API char *scm_to_stringn (SCM str, size_t *lenp, const char *encoding, scm_t_string_failed_conversion_handler handler); SCM_API size_t scm_to_locale_stringbuf (SCM str, char *buf, size_t max_len); SCM_API SCM scm_string_normalize_nfd (SCM str); SCM_API SCM scm_string_normalize_nfkd (SCM str); SCM_API SCM scm_string_normalize_nfc (SCM str); SCM_API SCM scm_string_normalize_nfkc (SCM str); SCM_API SCM scm_makfromstrs (int argc, char **argv); /* internal constants */ /* Type tag for read-only strings. */ #define scm_tc7_ro_string (scm_tc7_string + 0x200) /* Flags for shared and wide strings. */ #define SCM_I_STRINGBUF_F_WIDE 0x400 #define SCM_I_STRINGBUF_F_MUTABLE 0x800 SCM_INTERNAL void scm_i_print_stringbuf (SCM exp, SCM port, scm_print_state *pstate); /* internal accessor functions. Arguments must be valid. */ SCM_INTERNAL SCM scm_i_make_string (size_t len, char **datap, int read_only_p); SCM_INTERNAL SCM scm_i_make_wide_string (size_t len, scm_t_wchar **datap, int read_only_p); SCM_INTERNAL SCM scm_i_substring (SCM str, size_t start, size_t end); SCM_INTERNAL SCM scm_i_substring_read_only (SCM str, size_t start, size_t end); SCM_INTERNAL SCM scm_i_substring_shared (SCM str, size_t start, size_t end); SCM_INTERNAL SCM scm_i_substring_copy (SCM str, size_t start, size_t end); SCM_INTERNAL size_t scm_i_string_length (SCM str); SCM_INTERNAL int scm_i_string_is_mutable (SCM str); SCM_API /* FIXME: not internal */ const char *scm_i_string_chars (SCM str); SCM_API /* FIXME: not internal */ char *scm_i_string_writable_chars (SCM str); SCM_INTERNAL const scm_t_wchar *scm_i_string_wide_chars (SCM str); SCM_INTERNAL const void *scm_i_string_data (SCM str); SCM_INTERNAL SCM scm_i_string_start_writing (SCM str); SCM_INTERNAL void scm_i_string_stop_writing (void); SCM_INTERNAL int scm_i_is_narrow_string (SCM str); SCM_INTERNAL scm_t_wchar scm_i_string_ref (SCM str, size_t x); SCM_INTERNAL int scm_i_string_contains_char (SCM str, char c); SCM_INTERNAL int scm_i_string_strcmp (SCM sstr, size_t start_x, const char *cstr); SCM_INTERNAL void scm_i_string_set_x (SCM str, size_t p, scm_t_wchar chr); /* internal functions related to symbols. */ SCM_INTERNAL SCM scm_i_make_symbol (SCM name, scm_t_bits flags, unsigned long hash, SCM props); SCM_INTERNAL SCM scm_i_c_make_symbol (const char *name, size_t len, scm_t_bits flags, unsigned long hash, SCM props); SCM_INTERNAL const char *scm_i_symbol_chars (SCM sym); SCM_INTERNAL const scm_t_wchar *scm_i_symbol_wide_chars (SCM sym); SCM_INTERNAL size_t scm_i_symbol_length (SCM sym); SCM_INTERNAL int scm_i_is_narrow_symbol (SCM str); SCM_INTERNAL int scm_i_try_narrow_string (SCM str); SCM_INTERNAL SCM scm_i_symbol_substring (SCM sym, size_t start, size_t end); SCM_INTERNAL scm_t_wchar scm_i_symbol_ref (SCM sym, size_t x); SCM_INTERNAL void scm_encoding_error (const char *subr, int err, const char *message, SCM port, SCM chr); SCM_INTERNAL void scm_decoding_error (const char *subr, int err, const char *message, SCM port); /* internal utility functions. */ SCM_INTERNAL char **scm_i_allocate_string_pointers (SCM list); SCM_INTERNAL void scm_i_get_substring_spec (size_t len, SCM start, size_t *cstart, SCM end, size_t *cend); /* Debugging functions */ SCM_API SCM scm_sys_string_dump (SCM); SCM_API SCM scm_sys_symbol_dump (SCM); #ifdef SCM_STRING_LENGTH_HISTOGRAM SCM_API SCM scm_sys_stringbuf_hist (void); #endif SCM_INTERNAL void scm_init_strings (void); #endif /* SCM_STRINGS_H */ /* Local Variables: c-file-style: "gnu" End: */